Method of making enameled radiators



A ril 10, 1934. R. w. LOEFFLER METHOD OF MAKING ENAMELED .RADIATORSFiled Feb. 18, 1932 3 Sheets-Sheet. l

April 1934- R. w. LO EFFLER METHOD OF'MAKING ENAMELED RADIATQRS sSheets-Sheet 2 Filed Feb. 18, 1932 J April 10, 1934. R w LQEFFLER1,954,638

METHOD OF MAKING ENAMELED HADIATORS Filed Feb. 18, 1932 3 Sheets-Sheet 5Patented Apr. 10, 1934' UNITED STATES PATIENT oFFics METHOD OF MAKINGENAMELED BADIATORS Rudolph W; Loeflier, Baltimore, Md. ApplicationFebruary 18, 1932, Serial No, 593,716 Claims. (Cl. its-457.3)

In accordance with the present practice the great majority of heatingradiators for steam and hot water systems are made of cast iron.Theseradiators are defective in their operation and undesirablefor-several reasons. The production of thehollowcastings which arenecessary for their construction is expensive, the radiators are heavyto ship and handle and they are also. brittle and subject to failure onaccount of freezing, and by cracking due to blows orshocks.

On account of the thickness which is necessary to suflicient strength,they are very slow to heat resulting in a considerable loss ofefliciency and are correspondingly slow in responding to control,automatic or manuaL. Further, it is difiicult to so finish the externalsurface as to avoid accumulation of dirt so that they are apt to beunsanitary and unsightly, and the rough surface ordinarily presentedexternally of the radiator is not favorable to radiation.

The substitution of sheet steel or so called sheet iron for. the castmetal has been attempted, but with little success on account of theslight resistance presented by this material to, the corrosive action ofwater and the various chemicals contained in the water which isavailable for use in domestic and other heating plants. Further, suchradiators can not be made of one piece of metal and it has been founddiflicult to so join'the metal sheets as to avoid leakage at the jointsdueto corrosion or to deflection and straining on account of contractionand expan sion because of variation of internal pressure and crushing ordeflection of the radiator units when they are drawn together inassembling.

- The object of the present invention is to produce a radiator of sheetsteel or other sheet metal which is adapted to resist corrosion for anindefinite period, at least equal to the life of a cast iron radiator,and which consists .of plates so joined and so protected internally andexternally as to the joints that'there is no tendency to leak: ageeither from-straining, deflection, crushing or corrosion.

The invention relates to a method of making radiators preferably ofsheetiron or sheet steel,

- for which any other available sheet metal may be substituted, and tothe radiatorproduced in the practice of the method, and to the detailsof construction of this radiator whereby it is adapted to be soproduced. The method of the invention of the invention in the preferredform being so devised as to provide for the covering of the sheet metalwith a plurality of coats o; vitreous enamel which covers completely notonly the exposed internal and external surfaces of the radiator, but theedge portions of the sheet metal where they are clinched or otherwisejoined in combining the concave metal sheets to produce thehollow, unitsor sections of which the radiator isconstructed. 'The enamel whichcovers these edge portions being in accordance with one form of theinvention utilized'as a flux whereby it is caused to contribute to theeffectiveness of the welding operation assisting in the fusion of themetal so. as to produce a permanent joint which is proof againstcorrosion for an indefinite period at least equal .to and probablyexceeding the life of the average cast iron radiator.

It is of .interest that while the enamel serves in a satisfactory manneras a flux in joining the edges of the sheet metal plates to form theunits or sections that it may also be utilized in a different capacity,i. e., as a. cementitious material which intervenes between the clinchededges of the sheet metal plates serving to hold the plates togetherand-seal the seams or joints, the metal not' being actually fusedinaccordance with the. general acceptance of the term, the clinched edgesof the metal being on the'other hand sealed by the fusion and setting ofthe enamel.

features of construction whereby the units are to be supported fromwithin as to limit the deflec tion resulting'from the pressure appliedthereto The invention also relates to the details and i in joining theunits to assemble the radiator and the deflection due to internalpressure and to other features and details which contribute to theproduction on a commercial basis of a satisfactory radiator of thistype, i. e., one which is coated with vitreous enamel over the entireinternal and 9 preferably the entire external surface, the joints beingsealed and protected by the enamel and the edge portions ofthe sheetwhich are interengaged to form the seams or joints, being preferablycoated with enamel as .to the portions within the joint 1 orseam. I Inthe accompanying drawingsl have illustrated a radiator constructed inaccordance with the method of the invention illustrating constructiondetails of the invention and, the practice of the 1 method of theinvention, the construction shown embody the preferred detailscontributing to the production of a satisfactory enameled radiator ofthe type which is coated internally and preferably externally withvitreous. enamel.

away to show a portion in section.

Figure 3 is a section on the line 3, 3 of Figure 1 broken awayintermediately for convenience of illustration and showing the conditionof the enamel internally and externally after baking.

Figure4 is a fragmentary section on the same line showing one of thejoints or seams immediately after clinching the edges of the concavemetal sheets and prior to application of the ex! ternal coating, theedges not having been welded.

Figure 5 is a section on the line 5, 5 in Figure 1 of an assembledradiator of three br more sections, showing the manner of connecting theunits or sections at the top and bottom.

Figure 6 is a section through one of the seams by which the edges of thesheet metal plates are joined showingthe type of seam in which theenamel is utilized both as a sealing means and as a means for securingthe clinched edges 'of the sheet metal plates to form the unit, theplates being not necessarily otherwise connected by welding. The figurealso shows the sheet metal the plates being welded, the seam beingsealed from within by means of the enamel, the radiator being coatedinternally with the enamel which has been baked and fusedin positionthereon.

Figure .8 is a fragmentary section corresponding to Figure 5, showing amodification.

. Referring to the drawings by numerals, each of which is used toindicate the same or similar parts in the different figures, theconstruction shown is in its general outline very much like the castiron radiators in general use consisting of a number of units or hbllowsections having registering openings in the lateral faces at the top andbottom, the'units being assembled by drawing them together with theseopenings in registration.

The radiator indicated in a general way by reference character 1consists of any desired number of hollow members or units 2, 2, 2",which are preferably like or similar to the cast iron radiator units ofthe present existing practice as to their external outline and somewhatsimilar to them in the manner of connection except as to the variationof details provided in accordance with the invention to adapt theenameled sheet metal construction of the invention to use in theproduction of heating radiators.

In'accordance with this practice, the hollow units or sections 2 areprovided with opposite aligned openings 3 and 4 at the top-and 5 and 6at the bottom. In'assembling the radiator a suitable number of units 2are placed with their openings 3, 4, 12, 13 in registration and drawntogether by suitable tension members 7 and 8, the tension members 7 and8 being preferably threaded at their ends at 9 and 9' to engage frustoconical fittings or plugs 10 at the top and 11 at the bottom, which areseated in the flanged openings 3, 12, respectively, at the top andbottom of the radiator. These openings 3, 12 are shown' as in ternallyflanged at 14, 15, the flanges being turned inwardly and of frustoconical shape to fit the plugs 10 and 11, and each plug is apertured andthreaded at its inner end to engage the threads 9, 9' on the ends of thetension members 7, 8. In

the form of the invention shown the plug 10 at the top is solid and-theplug 11 at the bottom is apertured in the direction of the axis andthreaded to engage a steam or water pipe 16, the plug or fitting 11being apertured laterally at 17 to connect the pipe with the inside ofthe radiator, the end of the pipe being closed by the tension rod 8. Itwill be understood that the solid and apertured plugs may beinterchanged to give any desired method of connecting the radiators tothe system.

In accordance with the preferred form of the invention shown, the unitsor sections 2 are made with the openings at the top and bottominternally flanged as to the openings at one side, opening 3 beinginternally flanged at 14, opening 12 at 15, and the openings atthe'other side, i.-e. the right hand opening at the top of unit 2indicated by reference character 4, having an externally disposed flange18 which is frusto conical as in the previous instance. This flange issurrounded by an annular cavity 19 which provides for the reception of agasket or fibre ring 20. The opening on the right hand side of thissection or unit 2 at the bottom being exactly like the opening 4 at thetop is indicated by reference character 4 and need not be furtherdescribed. The second unit or section 2' and the remaining units orsection 2" need not be further described except that they are assembledin alternating relation so that the internal flanges face the externalflanges.

The frusto conical fitting or plug 10, at the top, duplicated at theopposite end of the series of units or sections 2 composing theassembled ra-.

diator, the duplicate plug being indicated by 10", and the tensionmember 7 is passed through the registering openings 3, 4, etc. from oneend to the other of the complete radiator, being engaged at its-oppositeends by the frusto conical plugs 10,

,10' which are turned up by means of a wrench totighten the units orsections in their assembled relation. It is also of interest that theopenings 3, 3' are surrounded by an annular seat or aperture 21 in whichis seated a fibre ring or gasket 22, which is covered by brass or othersheet metal washer 23 which may be coated with enamel and ,the plugs orfittings 10; 10", 11, etc. are made of non corrosive metal and ground,the openings 3,

3' being similar openings, if desired, ground as to the enamel thereinin frusto conical form to fit and receive the plugs.

It will be noted that the joints between the radiator sections at thetop and bottom are each formed by and with an externally flanged and aninternally flanged opening 3, 3', 4, 12, 13, so

that the adjacent openings are of opposite taper, it being understoodthat all of these openings are of increasing diameter from the insideoutwardly, and each section is connected to the adjacent one wiy meansof a double frusto conical fitting 24 hav- 7 ing a longitudinal axialaperture at 25 and a central peripheral flange 26, the fiange being ofsuch diameter as to fit into the annular space 19 and bear'against thegasket or ring 20 so that when the sections are drawn together by takingup onv apertured laterally at 28, the apertures being radiators, themanner of producing and the details .of construction of the hollowenameled sheet metal units to which the important features of theinvention relate will now be described. Each unit or section in the formof the invention shown consists of two concave metal plates 30, 31, thecurvature being so arranged and selected as to cause the plates whenjoined at their edges in any suitable manner, to enclose a cavitycorresponding to a radiator unit orsection of the desired.

size and shape. Each of these plates 30, 31 has its edges 'flanged at32, 33 in a single flat place in a manner suitable to provide forconnecting the plates by clinching as shown at 34 in Figures 3, 4, 6 and7. The first step in the performance of the method which is the subjectof the invention is the formation of these sheet metal sheets into thesections 30, 31 as described, the flanges being preferably of differentwidths and in any suitable form either straight or partially turned. The

. 'platesithus formed are first coated on the inside with a vitreousenamel paste 35 of the kind which is adapted to be baked o the metalwhereby it is Y fused and subsequently permitted to harden as anintegral sheet or coating of vitreous enamel. For

the purposes in hand the most flexible elastic compounds of enamel whichcan be obtained or produced are most satisfactory, a considerablecontent of borax being desirable when the enamel is employed as a flux.

The manner of initial coating is best illustrated in Figure4. This ispreferably applied before any bending or clinching of the edges. Themetal sheets are then baked to set the enamel 35 on the inside, whichmayconsist of any desired number of coats. The metal sheets are thenjoined by clinching the edges 32, 33, as particularly illustrated inFigure 4, after which the units or'sections are joined by welding at 43as shown'in Figure 7, i. e., by running an electric welding tool alongthe clinched edges 32, 33, or along exposed edge 32 in any suitablemariner. The section is then coated externally with enamel paste, itbeing understood that several coats of this enamel are applied, and thatall necessary precautious are taken to completely cover the joints andto fill in 'the angles and depressions as best illustrated at 37-.and39. Extra coatings of the enamel paste are applied at these points, if.necessary,it being understood that each coat of enamel is preferablyallowed to dry before. the next is applied. This portion of the methodmay be performed in any manner which may be found most suitable to thedesired result and to the material used., When the coating operation hasbeen completed, the various angles and depressions being covered asaforesaid, theunit is finished by placing it in an oven,

-; heatingthe enamel to a sufficient temperature to fuse it, after whichit is permitted to cool and harden, forming an integral vitreouscoating, covering the inside and the outside of the unit completely. Itis of particular interest that the enamel when thus fused completelycloses and preferred method.

seals the joints or seams on the inside: at 38 and on the outside itseals the crevices and depressions aroundthe joint as at 3'7 and 39giving a smooth external contour. The foregoing is the Referring now toFigure 6, it is of interest that the joint may if desired be sealed andcompleted, the welding step being omitted the unit or section in detailin Figure 6 being merely placed in the oven and heated to a temperatureat which the enamel is completely fused, after which it is permitted tocool and harden. By

this method the enamel is hardened between and around the.clinched edgesof the sheet metal 32, 33, 34, as indicated at 40. The joint is sealedon' the inside as indicated at 41 and on the outside the 'crevices anddepressions are completely filled and reduced to a pleasingandsatisfactory curvilinear contour as indicated at 42,.

Figure 8 shows an alternative form of interlocking .means whereby thefittings 10, 11, 24, etc., i.'e., the frusto conical plugs and thedouble frusto conical plugs may be omitted, the adjacent radiators beingprovided with male and female guiding sleeves, 45, 46 as to theiradjacent contacting portions, the respective male and female membersbeing surrounded by annular cavities 47, 48 which when placed inregistration by engagement of the male and female members 45, 46, form asingle annular cavity 49 which is adapted to contain a packing ring orgasket 50,

which serves as a yielding means between the radiator sections to closecontact between the seams, andtake up the pressure applied to theradiator sections or units in holding them in assembled relation. Thecrushing pressure thus applied to the units in assembling them is takenup by hollow struts 51, corresponding to the struts. 27 in Figure 5, anysuitable tension means as therod 52, the nuts 53 being available forthis purpose.

The method of the invention whereby radiators coated with enamelinternally and externally composed of sheet steel plates joined attheir' edges which are concealed by means of the enamel which may assistas acementitious material in the permanent fastening of the platescomposed of concave sheet metal plates welded or otherwise'permanently'joined at their edges and sealed externally and internallyby means of the vitreousenamel. The invention also includes, as alreadypointed out, the details of structure whereby a sheet metal radiatorcoated internally andexternally with vitreous enamel composed of unitsas described is adapted for assembly in series of such units in properregistration and suitably connected to form complete radiators for usein connection with domestic heating plants and for heating plants forheating rooms, apartments or buildings for human occupation.

It is of interest that all of the metal portions including'hollow studsor struts 27, the washers 23, and even the fittings 10, 11 and 24 andthe tension rods '7 and 8 may be coated with vitreous enamel to preventanyand all possibility of corrosion. This also adds to the pleasingeffect as the external view shows nothing but the enamel surface unlessit is preferred to finish the plugs '10, 11 which are exposed externallywith nickel or chromium or similar bright non corrosive metal.

Various advantages of the invention as the lightness, cheapness,efficiency, quick response to control, etc., due to quick heating andimproved radiation, improved appearance, increased sanitation and thelike have been fully pointed out;

discussed and emphasized in the preamble.

I have thus described a method of making heating radiators of sheetmetal, coated with enamel internally and externally, and sealed as tothe seams'or joints, and an article made in accordance with the methodof the invention, the description being specific and in detail in orderthat the method of practicing the invention and operating, applying andusing the same may be fully understood, however, the specific termsherein are used descriptively rather than in a limiting sense,

Lthe scope of the invention being defined in the claims;' What I claimas new and desire to secure by Letters Patent is: w

1. The method of making radiator-sections or units which consists inproviding concave metal sheets, coating them internally with vitreousenamel paste, placing the sheets with the concavities in registrationand the edges in contact,

sheets, coating them internally with vitreous enamel paste, placing thesheets with t e concavities in registration and the edges in contact,

welding the edges to form seams joining the metal sheets, coating thesheets externally with enamel paste and baking, to fuse the enamel andform an integral vitreous external and internal coating for the radiatorunit whereby the seams are sealed externally and internally by and withthe enamel. e

3. The method of making a sheet metal radiator which consists in formingconcave metal sheets, coating the 'inner surface with; enamel paste, andplacing the concavesheets in registration to form a hollow unitclinching and welding the edges and coating theexternal surface withenamel paste baking -to fuse the enamel forming a continuous vitreouscoating and sealing and protecting the joints.

4. The method of making radiators which consists in forming concavedsheet metal sections adapted to be joined at the edges to form hollowunits to be assembled in the production of a complete radiator coatingthe sections and edges internally with vitreous enamel paste, placingthe sections in registrationhaving their pasty edge portions in contact,joining the edges by crimping and welding the overlapping edges, wherebythe enamel paste on said overlapping edge is utilized 1 as a weldingflux, coating the radiator externally with enamel paste and heating tofuse the enamel whereby it is caused to forman integral. vitreouscoating, sealing the joints or seams at the edge of the plates.

5. The method of making radiatorunits or sections which consists inproviding concaved metal sheets adapted to be assembled by'joining themat the edges to form hollow units, coating the sheet metal plates andedge portions internally with vitreous enamel paste, placing thesections in registration with their coated edges in contact to formahollow radiator unit, crimping the edges together forming a seamwhereby the metal sheets are joined, coating the external surface withRUDOLPH W. LOEFFLER.

